As for trying Firefox; WISE MOVE!

The majority of Spyware, Scumware and Malware manage to make their way onto PC's through exploits in Internet Explorer and it's Activex feature, but there are still plenty of programs you can download that will contain masses of spyware, a family member recently brought their PC to me to have cleaned, it was completely full of spyware and was barely unusable, all they did was install a screensaver they got off a website, so as you see picking a safe browser is only part of the solution, picking your downloads wisely is just as important.